1. Field of the Invention
The present invention relates to an apparatus for a semiconductor device and more particularly, to a chuck supporting a substrate and controlling a temperature.
2. Discussion of the Related Art
Recently, a new material field in which development and treatment of new materials has been rapidly grown as development of science and results of the new material field become driving force of development in a semiconductor industry.
A semiconductor device is a large scale integrated circuit (LSI) which is fabricated through subsequent deposition and patterning processes of thin films on a substrate and theses processes are performed in a chamber which is a closed reaction vessel. A chuck is equipped in the chamber to fix the substrate. Generally, the chuck is classified into two types: a vacuum chuck fixes the substrate by applying a vacuum at its center portion; and an electrostatic chuck fixes the substrate by using a mutual action between the substrate and an electrostatic field generated by applying a direct current.
In a semiconductor industry, a method using a plasma is developed according as a substrate is enlarged and a pattern of a semiconductor device is fined. In an induced coupled plasma (ICP) method, as an example of a plasma-generating method, a time-varying electric field is induced in a chamber including gaseous materials by using a radio frequency (RF) voltage and a substrate is treated by using a plasma generated by the time-varying electric field. An RF electrode is equipped in the chamber and controls an impact energy of a plasma ion. Since a temperature control of the substrate influences characteristics of a fabricated device such as a uniformity, a critical dimension, a profile and a repeatability, a temperature control unit is included in the chamber for an effective temperature control. Moreover, a direct current electrode can be equipped in the chamber to fix the substrate for the electrostatic chuck.
FIG. 1 is a schematic perspective view showing a chuck of a related art apparatus for semiconductor device. As shown in FIG. 1, a chuck 30 includes a chuck body 30a and a chuck supporter 30b. The chuck body 30a having a plate shape is horizontally disposed in a chamber (not shown) and a substrate is loaded thereon. The chuck supporter 30b having a pipe shape supports the chuck body 30a and penetrates the chamber. Moreover, an RF electrode, a temperature control unit and a direct current (DC) electrode can be equipped in the chuck body 30a. The chuck body 30a is horizontally combined with one end of the chuck supporter 30b. The other end of the chuck supporter 30b is disposed at an exterior of the chamber and is closed with a base lid 30c of a plate shape to prevent an injection of impurities or gaseous materials into the chamber from exterior of the chamber.
The chuck 30 moves up and down by an external driving means “M” such as motor with the chamber penetrated. The RF electrode, the DC electrode and the temperature control unit equipped in the chuck body 30a are connected to the external means for their driving. Accordingly, a plurality of terminals 32 connected to the RF electrode, the DC electrode and the temperature control unit are protruded from an outer surface of the base lid 30c. The plurality of terminals 32 can be formed on an outer surface of the chuck supporter 30b according to purposes. One terminal connected to the RF electrode in the chuck body 30a is connected to an external RF power supply 76 and functions as an RF input terminal 32a. Generally, an impedance matching unit adjusting an impedance of an RF voltage is interposed between the RF input terminal and the RF power supply 76. The impedance matching unit is equipped in a matching box 74 of cubic shape and the RF input terminal 32a of the chuck 30 is electrically connected to the matching box 74 through a wire 78.
However, the chuck 30 has some disadvantages in use. Since the chuck 30 and the matching box 74 are spaced apart from each other, a connection between the chuck 30 and the matching box 74 is not reliable. Furthermore, since a path from the matching box 74 to the RF input terminal 32a is long for power transmission, an RF power loss is inevitable. The chuck 30 moves up and down by the external driving means “M” such as motor with the chamber penetrated, while the matching box 74 is spaced apart from the chuck 30 and fixed in exterior. Accordingly, a reliability of connection is reduced. Moreover, the shorter wire 78 connecting the RF input terminal 32a of the chuck 30 and the matching box 74 is better for effective transmission of the RF power, while the wire 78 should have a specific length not to disturb an independent up-and-down movement of the chuck 30. Accordingly, the RF power is inevitably lost.